The identification of new and improved synthetic methods for making ligand precursors which are used to construct highly active polymerization catalysts is of importance to the polymer industry.
The known ligand precursor 1,3,4-(SiMe3)(C6F5)(n-alkyl)C5H3 has been successfully employed in the synthesis of phosphinimine complexes which are highly active olefin polymerization catalysts.
Previously published methods for making the ligand precursor 1,3,4-(SiMe3)(C6F5)(R)C5H3 (where R is n-propyl, n-butyl, or n-hexyl), although effective in terms of overall yield, involved the isolation of intermediates and required the use of several work-up steps, as well as time consuming filtrations steps. Multiple reaction vessels were also required. See for example U.S. Pat. Nos. 7,531,602, 7,064,096, 7,321,015 and 7,323,523.